Dairy cattle are typically managed to maximize milk production. One component of this is to maximize cow comfort, in their housing, in a cost effective manner. To improve and manage cow comfort dairy cows are typically housed in free stall barns.
An excellent review of some typical aspects of free stall management decisions and materials can be found in publication number EBAE 176-93, published by North Carolina Cooperative Extension Service, by James C. Barker, entitled Used Tires in Dairy Free Stall Bases. Much of the information contained in that publication is reproduced in the background information contained herein.
Original stalls had soil bases contained by a concrete curb and covered with sawdust, wood shavings, straw or other moisture-absorbent material. As cows shifted position on these surfaces, holes were dug and wallowed out, which if not filled could cause injury or become a collector for waste materials and moisture. The potential for mastitis and other diseases increases when cows use these imperfect stall bases. Obviously, considerable maintenance is required to keep the stalls in suitable condition.
Other stall surface materials such as concrete, concrete with rubber mats or outdoor carpet, or clay bases covered with mats or sand which could be easily smoothed have been tried to overcome the disadvantages of soil bases. Usually these hard surfaces were covered with a thin layer of wood shavings or lime to provide cushioning for the cow and to absorb moisture. Each of these base materials have their advantages from a management standpoint, but have disadvantages regarding cow comfort. Cows seem to prefer softer surfaces making some of the harder bases less desirable. The mats must be extremely tough and durable to keep from being rendered unusable. Sand and lime provide problems with manure handling systems, particularly liquid manure equipment. Competition for sawdust or wood shavings has rendered these materials expensive or hard to obtain.
In looking about the farmstead and surrounding community, one can observe that there are a number of materials discarded because they no longer serve the purpose for which they were originally intended, or are now viewed as waste materials. It is advantageous to find uses for some of these materials through recycling rather than continue to allow them to litter the landscape or take up valuable space in landfills. One such material is used automobile tire carcasses. Some communities stockpile old tires near landfill sites. Other sources are automobile service stations, tire service centers and farmsteads. Usually, these tires are available for the asking or are very inexpensive. Whole used tires can be used as a dairy free stall base material to stabilize the soil while providing a soft cushioned surface.
In fact, tires have been used for a number of years in dairy free stalls at the Piedmont Research Station near Salisbury, N.C. and more recently in a number of other states. Cows have accepted the tires very well and seem to prefer the soil-embedded tires in stalls to alternative surfaces. The digging of holes in stall surfaces has been virtually eliminated.
The tires are typically embedded firmly in the soil. A disadvantage of using whole tire carcasses is that if the soil is not packed in and around the tires, cows can move them out of place. Tires for a 13- or 14-inch diameter wheel work best in a 48-inch wide stall. Larger diameter or wider tires may be used but require more soil depth and packing. They should be placed side-by-side and touching. Six tires are required for each stall.
If fine-textured soil is thoroughly packed inside and around the tires, there does not seem to be a need to cut or drill holes in the bottom sidewall since moisture and urine do not seep through the soil and accumulate in the tire. Some producers initially fasten the tires together with lag bolts to help anchor them although this also seems unnecessary if they are installed properly. Tires toward the front of the stall should be slightly higher with a 4- to 6-inch slope from front to rear. Tires at the rear of the stalls should be about even with the top of the curbing.
Use of a sand layer underneath the tires facilitates positioning of them relative to the stall surface and helps drain moisture away from the stall base. Soils containing some silt or clay or other fine-textured materials work best for packing in and around the tires. Care must be taken to pack soil inside the tire carcass as well as around it. Wooden spreader blocks are helpful for opening up the carcass to get soil inside the tire. Soil should be filled and packed to the top of the tire tread.
A thin layer of bedding material such as wood shavings, composted manure solids, or lime is usually spread over the stall floor surface. A minimum of maintenance weekly typically keep these surfaces dry and comfortable for the cow.
A significant disadvantage to using whole tire carcasses as free stall bases is the work required to position and anchor them properly. It is generally considered to be impractical, and therefore unuseable, to employ whole tires in free stall bases and still achieve other typical management goals. A 100-stall barn requires the bases of each stall to be excavated and prepared to receive the tires. Six tires in each stall (a total of 600 tires) requires the addition and packing of soil by hand labor. The durability of tires in free stalls seems to be about 5 years if they are heavily used. The cows, however, seem to prefer tire-surfaced stalls and appear to be comfortable. Bedding costs and maintenance can be significantly reduced. Cow cleanliness is much improved and the potential for udder diseases reduced because the cows are more likely to use the clean, dry stalls. The incidence of bruised hocks and leg abrasions is reduced when compared to harder more abrasive stall surfaces.
In summary, the use of whole automobile tire carcasses in dairy free stall bases is yet another example of a management choice that dairymen can make that also contributes to their communities by recycling a product otherwise considered a waste material into an inexpensive and functional part of their production facilities.
There still remains a need for means to improve dairy cow comfort, particularly as it relates to cows' use of free stalls.